Semiconductor integrated circuit and imaging device

1. A semiconductor integrated circuit, comprising:

a pixel circuit configured to photoelectrically convert incident light to a pixel signal;

a pair of TFETs (Tunnel Field Effect Transistors) that includes a first TFET and a second TFET, wherein the pair of TFETs is configured to:

amplify a difference between the pixel signal and a reference signal, wherein the reference signal changes with time; and

output the amplified difference as a differential amplification signal; and

a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) configured to supply a constant current to the pair of TFETs, wherein

a source of the first TFET and a source of the second TFET are connected to a drain of the MOSFET, and

a first area of a gate of the MOSFET is substantially equal to each of a second area of a gate of the first TFET and a third area of a gate of the second TFET.

2. The semiconductor integrated circuit according to claim 1 , further comprising

a plurality of pixel circuits in a two-dimensional lattice shape, wherein

the plurality of pixel circuits includes the pixel circuit, and

a respective pair of TFETs is for each pixel circuit of the plurality of pixel circuits.

3. The semiconductor integrated circuit according to claim 2 , further comprising

a data storage unit configured to acquire and store data, that indicates time until the differential amplification signal changes to a value different from an initial value, as pixel data.

4. The semiconductor integrated circuit according to claim 3 , further comprising a plurality of data storage units, wherein

the plurality of data storage units includes the data storage unit, and

a respective data storage unit of the plurality of data storage units is for each pixel circuit of the plurality of pixel circuits.

5. The semiconductor integrated circuit according to claim 3 , wherein the data storage unit is for each column that includes a set of pixel circuits, of the plurality of pixel circuits, in a specific direction.

6. The semiconductor integrated circuit according to claim 1 , further comprising:

a substrate;

an N-well layer on the substrate;

a pair of N layers including an N-type semiconductor; and

a P layer including a P-type semiconductor, wherein

the P layer and the pair of N layers are on the N-well layer,

the P layer is between the pair of N layers on the N-well layer,

each source of the pair of TFETs is in the P layer, and

each drain of the pair of TFETs is in the pair of N layers.

7. An imaging device, comprising:

a pixel circuit configured to photoelectrically convert incident light to a pixel signal;

a pair of TFETs (Tunnel Field Effect Transistors) that includes a first TFET and a second TFET, wherein the pair of TFETs is configured to:

amplify a difference between the pixel signal and a reference signal, wherein the reference signal changes with time; and

output the amplified difference as a differential amplification signal;

a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) configured to supply a constant current to the pair of TFETs, wherein

a source of the first TFET and a source of the second TFET are connected to a drain of the MOSFET, and

a first area of a gate of the MOSFET is substantially equal to each of a second area of a gate of the first TFET and a third area of a gate of the second TFET;

a data storage unit configured to acquire and store time information, that indicates time until the differential amplification signal changes to a value different from an initial value, as pixel data; and

a processing unit configured to perform a specific processing on the pixel data.